Distance between lat/lon points

I need to determine the distance (or a reasonable approximation of it) between two sets of latitude / longitude coordinates. Preferably in a standard distance measurement, e.g. miles. Data is available in the following format: 4542.82691N,01344.26820E [login to view URL],[login to view URL] The application must run on Python v. 1.5.2+. Built in modules: imp, marshal, md5, sys are available (it is not possible to recompile Python). I would expect the deliverable to be e.g. a function that accepts 4 arguments: start lat, start lon, end lat, end lon, and returns the distance between them. It should be reasonably robust / commented code. Update: To clarify, this code must be Python only, I will not accept bids for code running on any other language. Update 2: By "Built in modules: imp, marshal, md5, sys are available" I meant that those are the *only* built in modules available (this is an embedded platform). Update 3: The type float is not available - when trying to use floats, the message "RemovedFeatureError: FloatType has been removed" is displayed (thanks to x2 bidders for the info). Update 4: It is probably also worth mentioning the device has 1 MB of RAM available (a reasonable proportion of which is already being used), and 3MB of storage (around 0.8MB max is available for the bidder). ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform The application must run on Python v. 1.5.2+. Built in modules: imp, marshal, md5, sys are available (it is not possible to recompile Python).